可这样：syms x yf=x^2*sin(x+y^2)+y^2*exp(x+y)+5*cos(x^2+y);dfdy=diff(f,y)ezsurf(f,[-2 10 -2 10])title('原函数图像')ezsurf(dfdy,[-2 10 -2 10])title('偏导数dfdy图像')
